COBE, NASA's Cosmic Bacground Explorer. Note especially the DMR (Differential Microwave Radiometer) pictures of the cosmic background radiation.
Cosmology, all of it, with many computer simulations from NCSA (National Center for Supercomputing Applications)
Einstein Online: a large database, with many quotes and pictures
Hawking lectures on Origin of the Universe and Baby Universes
Hubble Space Telescope's home page has much to offer, mostly under Public, including:
Simulations of galaxy creation by computers at Los Alamos National Lab